地下采动条件下露天矿边坡覆岩移动规律研究

Study on the Movement Law of Overlying Strata in an Open-pit Slope during Underground Mining

以安太堡矿为研究背景,采用相似模拟实验研究在井采采动条件下边坡覆岩移动规律、地表沉降及周期来压下上覆岩层跨落状况。结果显示:井采条件下,工作面存在大小不同的周期来压,初次来压28cm(56m)、跨落高度3cm(6m)、跨距21cm(42 m);当工作面推进到90cm(180 m)时,达到充分采动,离层和裂隙向坡体表面和台阶处衍生,随时有发生截断的危险,左跨落角为57°,右跨落角为58°;随着井采工作面不断向前推进,采空区上方覆岩也在不断发生沉降,最大沉降值为8.9mm(1.78m),并且由于上覆岩层的不断跨落,在坡体失去平衡状态下,致使地表发生沉降,最大沉降值为2.9mm(0.58m)。

Taking Antaibao mine as a research background, similar simulation experiments were carried out to study the move- ment law of overlying strata, the surface subsidence and the failure of overlying strata under periodic weighting. The results showed that during underground mining, the working faces had different periodic weightings as follows, the first weighting of 28 cm （56 m）, the failure height of 3 cm （6 m） and the span of 21 cm （42 m）. When the working face went forward to 90 cm （180 m） , full mining was achieved. The abscission layers and cracks derived to the slope surface and the steps, and the risk of truncation would happen at any time. Meanwhile, the left cross angle was 57~, and the right cross angle was 58~. When the working face continued to move forward, the overlying strata at the top of goaf constantly had settlement, and the maximum settlement value was 8.9 mm （1.78 m）. The continuous collapse of the overlying strata resulted in the surface subsidence when the slope was out of balance, with the maximum settlement of 2.9 mm （0.58 m）.